Dear CoCo aficionados, We received 12 tools for CoCo 2021: http://project-coco.uibk.ac.at/2021/participants/index.php Like last year, we solicit secret problems that will be selected for the competition. To make this manageable, everyone can submit at most two problems per category but tool authors may only submit to the categories in which they participate. Multiple authors of the same tool count as one here. Submission is via email to the CoCo SC. Problems should be submitted as attachment (one file per problem) and follow the official format as specified in the description of the CoCo categories: http://project-coco.uibk.ac.at/2019/categories/index.php The comment field must contain the category to which the problem is submitted. The SC will enter the received problems in COPS. Problems that don't adhere to the official syntax will be rejected. The deadline for receiving the secret problems is July 10 (AoE). CoCo SC coco-sc@informatik.uibk.ac.at